Scala is a well engineered modern successor to Java. It's a statically-typed functional/OO language with curly-brace syntax, pattern matching and type inference that runs on the JVM. Scala's libraries are well-thought-out and consistent. And, it's type system is some serious rocket-science.

Principles for Good Design

The class was a great introduction to the language and some ideas that will come in handy in any language. I had a lot of fun with it. Odersky wrapped up the course with some principles for good program design.